Non-sparking electric switch



(N0 Model.)

G. E. PAINTER. NON SPARKING ELECTRIG SWITCH.

No. 488,899. Patented Dec. 27, 1892.

Zin 0/ UNITED STATES PATENT OFFICE.

GWYNNE E. PAINTER, OF BALTIMORE, MARYLAND.

NON-SPARKING ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 488,899, dated December27, 1892.

Application filed March 11, 1892. Serial No. 424,540. (No model.)

To all whom it may concern.-

Be it known that I, GWYNNE E. PAINTER, a citizen of the United States,residing at Baltimore, in the State of Maryland, have invented certainnew and useful Improvements in Non-Sparking Electric Switches, of whichthe following is a description, reference being had to the accompanyingdrawings, and to the letters and figures of reference marked thereon.

My invention relates to electric switches and particularly to that classof switches used upon incandescent circuits.

The object of my invention is to prevent the destructive sparking at thecontacts occurring upon the making and breaking of the circuit. Broadlyspeaking, I accomplish this end by adding a contact to thoseusuallyemployed which makes circuit before the main contacts come intouse and breaks it after they have gone out of use so that thesparking,inevitable in all circuit-breaking switches, is confined to theadded, or, supplemental, contact. This is preferably a thrust contactand not a rubbing or dragging one. The reason for this is that whererubbing contacts are used the sparking roughens the contact surfaces andan unnecessarily strong effort is required to work the switch because ofthe friction caused thereby.

I have illustrated and described my invention in combination with anelectromagnetic two-pole switch intended to be used upon chandeliers andin places not easily accessible. The device is more appropriatelyapplicable to such a switch, as its perfect operation depends upon theeiiiciency of the electromagnets which are the actuating power, and theywill not work well, sometimes not at all, if the contacts are roughenedby sparking and the friction between them consequently much increased.

In the drawings-Figure 1 is an end view of a switch such as describedabove, with some of its parts broken away. Fig. 2 isasectional Viewtaken on the line oc-w of Fig. 1. Fig. 3 is an enlarged detail of thedevice shown in Fig. 1. Fig. 4is a detail modification. Fig. 5. is aview in diagram showing the circuit connections.

As seen in Figs. 1 and 2, a plurality of electro-magnets M, M, aremounted upon a suitable base X, in any convenient manner, and this baseis not more particularly described as it forms no part of the presentinvention. A rocking lever L, is pivoted above the magnets M, andarmatures A, A, are fixed to it in proximity to the poles of saidmagnets.

In the end view in Fig. 1, one pair of the magnets M, is shown and thearmature on one end of the lever under the influence thereof. Fig. 2being in section, only one of each pair of magnets is shown.

The rocking lever L, is provided with insulating blocks I, 1, whichextend beyond the ends of said lever and are securely attached thereto.Upon these blocks, or inserted into them, are conducting blocks 0, O,which are placed at the upper edge of one and at the lower edge of theother of the blocks 1, I, so that in one position of the lever bothpairs of the contacts E, E, will be in contact therewith and in theother out of contact, so that the circuit will be broken on both sides,that is, both positive and negative, at one movement of the lever. Oneof the contacts E, in Fig. 1,is broken away to show the application ofmy anti-sparking device which is fixed to a bracket B, and to which oneof the spring contacts E is attached. The bracket B, is fixed in anysuitable manner to the base X, that supports the electro-magnets M, M,and extends upwardly and has an offset 0, at the top. This offset iswide enough to project beneath the contact block I, and it is bored toreceive a pin P, which passing therethrough makes a thrust contact witha conductor 0, leading down from the block I, and terminating in a flathead h.

At the outer extremity of the offset 0, is fixedaspring S, which is longenough to reach to and beneath the pin P, to which it is fixed. Thespring S, presses the pin P,upward with a constant pressure and itsproximity to the conductor 0, may be adjusted by the screw to, so thatthe moment of its contact with the said conductor is accuratelydetermined. The pin P, does not touch the head of the conductor leadingfrom the contact block 0, except when it is depressed, but must do sobefore contact is made between the spring contacts E, and the block 0,as otherwise the sparking would take place between the wrong contactsand the device be useless. The range of throw of the supplementalcontact or pin P, must be great enough to establish contact beforetheregular circuit contacts E, on one side of the circuit and maintainit after these main contacts have broken circuit. This can easily beadjusted by means of the screw to.

In Fig. 1, I have indicated the contact surface of the spring contact E,by a dotted line 1, and a comparison willshow that the distance betweenthe said line and the block 0, is less than the throw remaining to thepin P, which is only limited by the spring S, coming into contact withthe set screw it. This is also shown in Fig. 3, where neither thecontact E, nor the pin P, have completed contact. By a comparison itwill be seen that the contact E, represented by the line 1, will notreach the block 0, until after the pin P, contacts with the head h, ofthe conductor 0. It is of course obvious that the contact E will leavethe block 0, before the pin P, breaks contact with the head 71, ofconductor 0.

The result of the operation described will be that whatever sparkingtakes place will be between the pin P, and the head of the conductor c,and the contactsurfaces of the blocks 0, C, and contacts E, E, willremain smooth and offer the least resistance to the operation of thelever Ii, actuated by the electro-magnets M.

Referring now again to Fig. 2, it will be seen that the metallic blockupon the insulating block I, is wider than the one upon the block I, andthat the contacts E, will therefore complete one side of the circuitbefore the contacts E do the other. This is, of course, necessaryinorder that circuit may be completed and current flow through thesupplemental contacts before it does through the contacts E. The pin P,may make contact either simultaneously with the contacts E, or at anytime after and before the contacts E. In single pole switches'thesupplemental contact would make contact before the single main contactor contacts. The pin P, and conductor 0, with its head 71, could be maderemovable at small expense and the life of the switch much prolonged.

In Fig. 4 I have shown a modification of my device the principaldifference being in using a spiral spring instead of a flat one. Here ashort bracket 2', is fixed to the largerbracket B. The bracket t,supports a spring .9, and also serves to guide one end of the pin P.

As shown in Fig. 5 upon a partial depression of the lever L the circuitwill be from source through conductor 1, to bracket B, thence throughspring S, pin P, thereon, through the head h, of pin 0, to the oppositesupplemental contact, bracket, and conductor 2, to translating devices.A further depression of the lever L, will bring the contacts E, upon theblock O,and the circuit willbe com pleted through the main contacts.

In the diagram I have shown the supplemental contacts making circuitthrough the head h, of a single pin 0, but itwill be understood that theoperation would be the same if two pins were used, one for each contactand the circuit completed through the block C. One pair of the magnetsM,are shown as being operated by a battery Z), through conductors 3, 4,the circuit being controlled by a switch 1). A similar circuit maybeprovided to operate the opposite pair of magnets.

It will be understood that the relative area of contact surface of themain and supplemental contacts must be properly proportioned withrespect to the current carried as, if the area of the supplementaldevice be too small, it would be ineffectual.

Many modifications of the details of myinvention might easily be madewithoutdeparting from the spirit thereof, and I do not, therefore,confine myself to the precise construction shown.

Having described my invention, what I claim and desire to secure byLetters Patent 1s:-

1. The combination in an electric switch of a rocking lever, meansforoperating the same, a contact bar upon each end of thelever, maincircuit terminals completing circuit through said bars and asupplemental contact completing circuit in advance of the mainterminals.

2. The combination in an electric switch of a rocking lever, means foroperating the same, a contact bar upon each end of the lever, maincircuit terminals completing circuit through said bars, and two or moresupplemental contacts completing circuits in advance of the mainterminals.

3. The combination in an electric switch of a rocking lever, means foroperating the same, a contact bar upon each end of the lever, bracketssupporting the main terminals of the circuit in proximity to said bars,and supplemental contacts upon two or more of the bracke ts completingcircuit before the main terminals.

at. The combination in an electric switch of a rocking lever, means foroperating the same, a contact bar upon each end of the lever, maincircuit terminals completing circuit through said bars and supplementalspring contacts making a thrust contact with the bars and completingcircuit through them in advance of the main terminals.

In testimony whereof I hereto affix my signature in presence of twowitnesses.

GlVYNNE E. PAINTER.

Witnesses:

G. ALLEN MUELLEN, ALICE O. ILGENFRITZ.

IIO

